Free floating piston reactor



Aug. 4, 1959 J. w. SCOT-T, JR 2,898,199

FREE FLOATING PISTON REACTOR Filed Deb. 26, 1956 REACTANT IN REACTANT IN I3 I 1/ 73 L l PRODUCT PRODUCT OUT I OUT INVENTOR JOHN W scorr, JR.

United States Patent FREE FLOATING PISTON REACTOR John W. Scott, Jr., Ross, Calif., assignor to California Research Corporation, San Francisco, Calif., a corporation of Delaware Application December 26, 1956, Serial No. 630,633

2 Claims. (Cl. 23-252) The present invention relates to the production of chemical reactions requiring high temperatures for brief periods of time, and more particularly to apparatus for producing said chemical reactions.

'Various chemical reactions may be driven to completion without undesirable side effects only by the application to the reactants of high temperatures for brief intervals. For example, nitrogen and oxygen may be so reacted to produce nitric oxide. From nitrogen oxides so produced, ammonia, nitric acid, etc., may be obtained relatively easily.

It has been known heretofore to ignite an explosive gaseous mixture containing nitrogen and oxygen under suitable conditions such that the resulting temperature rise will be suflicient to cause a portion of the two gases to combine to form nitric oxide. It has been known to accomplish such reactions in the combustion chambers of various engines where there were available the requisite conditions of high temperatures for short times. This procedure has left much to be desired, however, because of the inherent inefiiciencies, the dilution and contamination of the reaction products with combustion products, and other factors. It is therefore an object of this invention to provide apparatus for accomplishing chemical reactions at high temperatures for brief periods, in which the reactants and resulting reaction products are kept separate at all times from the fluids supplying the energy to produce the requisite temperatures.

In accordance with the present invention there is provided apparatus for producing chemical reactions comprising a free piston engine having a free piston reciprocable in a main cylinder, at least one secondary cylinder, a secondary piston reciprocable in said secondary cylinder in response to reciprocation of said main piston, means for introducing reactants into said secondary cylinder, means for withdrawing reaction products from said secondary cylinder, and means for reciprocating said main piston in said main cylinder, whereby said secondary piston is reciprocated in said secondary cylinder to compress the contents thereof with resulting high temperatures.

The invention will further be understood, and other objects, features, and advantages thereof will become apparent, from the following description when read in connection with the accompanying drawing, in which the single figure illustrates a sectional view of an embodiment of the free piston apparatus of the invention, together with auxiliary equipment.

Referring now to the drawing, main piston 1 reciprocates in main cylinder 2 in housing 3 between the two locations in which piston 1 is shown by dotted lines. The motive power for piston 1 is provided by conventional methods. The motive power may be, for example, provided by compressed air introduced into cylinder 2 through, line 4 and compressor 5. Alternatively, the motive power may be provided, for example, by liquid fuel injection into cylinder 2 through line 6 and injection of combustion air through line 4 and compressor 5. A still further alternative is to introduce an air/ gas mixture through line 4 and compressor 5 into cylinder 2. In the latter two alternatives the combustible mixture in cylinder 2 is ignited by conventional methods. As piston 1 reciprocates in cylinder 2 by the alternative ap plication of power to one exposed face and then the other of cylinder 1 the contents of cylinder 2, alternately expelled from one and then the other thereof, may be directed through line 7 to drive a turbine 8, exhausted through line 9. If desired, a mechanical driving means connection 10 may be provided to permit turbine 8 to drive compressor 5.

Secondary pistons 11 reciprocate in secondary cylinder 12 in response to the reciprocation of main piston 1 in main cylinder 2. The location of the free end of each piston 11 at the end of its compression stroke is indicated in the drawing by a dotted line. Chemical reactants, for example, N and 0 are passed into cylinders 12 through passageways 13 and are maintained in the reaction chambers formed by the closed ends of cylinders 12 until they are reacted under high temperatures in cylinders 12 caused by compression of the reactants in cylinders 12 by pistons 11. The reaction products are then withdrawn from cylinders 12 through passageways 14. Passageways 13 and 14 are suitably blocked by conventional means (not shown), for example, valves, during the compression stroke of each piston 11. Exemplary orders of magnitude for peak temperatures and times thereof in cylinder 12 reaction chambers during compression are about 4000 R. and about 2 milliseconds, respectively. During the brief periods of temperature rise and fall in the cylinder 12 reaction chambers, only about 10% of the energy input to the apparatus is lost through the cylinder 12 reaction chamber walls as heat.

It will be apparent that numerous changes in the arrangements and modes of operation of the free piston engine apparatus of the present invention may be made without departing from the spirit thereof and all such changes are intended to be embraced by the following claims.

I claim:

1. Apparatus for accomplishing chemical reactions which require high temperatures for brief periods of time, which comprises a free piston engine having a main cylinder and a main free piston therein, at least one sec-.

ondary piston mounted on said main piston as an extension thereof, a secondary cylinder in which said secondary piston reciprocates during reciprocation of said main piston in said main cylinder, inlet means for introducing chemical reactants into said secondary cylinder, outlet means for withdrawing reaction products from said secondary cylinder, said inlet and outlet means being so located that they are closed by said secondary piston during a portion of the compression stroke and exposed by said secondary piston on the expansion stroke, means for reciprocating said main piston whereby said reciprocating secondary piston alternately closes said inlet and outlet means and compresses the reactants thereby trapped in said secondary cylinder, and opens said inlet and outlet means to permit introduction of additional reactants and withdrawal of reaction products at substantially lower pressures than the peak pressures in said secondary cyl- ,inder.

2..- Apparatus for accomplishing chemical reactions which require high temperatures for brief periods of time, which comprises a free piston engine having a main cylinder and a main freepiston therein, at least one secondary piston mounted on said main piston as an extension thereof, a secondary cylinder in which said secondary piston reciprocates during reciprocation of said main piston in said main cylinder, inlet means for introducing chemical reactants into said secondary cylinder 2,898,199 3 V 4 at a point spaced from the closed end thereof, outlet References Cited in the file of this patent means for withdrawing reaction products from said secondary cylinder at a point spaced from the closed end UNITED STATES PATENTS thereof, the inward travel of said piston extending past 1,132,381 Porter Mar. 16, 1915 each of said points toward the closed end of said cylinder 5 2,232,631 R i k F b, 18, 1941 to compress reactants therein independently of the pres- 2,814,551 Broeze et al Nov. 26, 1957 sure in said inlet and said outlet means, and the outward travel of said piston providing for expansion of said FOREIGN PATENTS reactants in the closed end of said cylinder before they 116,658 Switzerland Dec. 16, 1926 are released through said outlet means. 10 

1. APPARATUS FOR ACCOMPLISHING CHEMICAL REACTIONS WHICH REQUIRE HIGH TEMPERATURES FOR BRIEF PERIODS OF TIME, WHICH COMPRISES A FREE PISTON ENGINE HAVING A MAIN CYLINDER AND A MAIN FREE PISTON THEREIN, AT LEAST ONE SECONDARY PISTON MOUNTED ON SAID MAIN PISTON AS AN EXTENSION THEROF, A SECONDARY CYLINDER IN WHICH SAID SECONDARY PISTON RECIPROCATES DURING RECIPROCATION OF SAID MAIN PISTON IN SAID MAIN CYLINDER, INLET MEANS FOR INTRODUCING CHEMICAL REACTANTS INTO SAID SECONDARY CYLINDER, OUTLET MEANS FOR WITHDRAWING REACTION PRODUCTS FROM SAID SECONDARY CYLINDER, SAID INLET AND OUTLET MEANS BEING SO LOCATED THAT THEY ARE CLOSED BY SAID SECONDARY PISTON DURING 